1. Field of the Invention
The present invention is related to a disc drive.
2. Description of the Prior Art
There are various disc drives which playback or record/playback optical discs such as a CD-ROM, CD-R, DVD and the like These disc drives include a box-shaped main body, a disc tray which is movable between a position for loading an optical disc in the main body and a position for ejecting the optical disc, and a sled mechanism unit provided inside the main body. The sled mechanism unit is constructed from an optical disc rotational drive mechanism which rotates a loaded optical disc, an optical pickup (optical head), and an optical pickup moving mechanism which moves the optical pickup in a radial direction of the optical disc, and all these elements are arranged on a chassis.
The sled mechanism unit is provided in a manner that enables pivotal movement about an axis around the vicinity of the rear end portion thereof with respect to the main body. When the disc tray is ejected, the front portion of the sled mechanism unit is rotated downward so that the sled mechanism unit does not interfere with the disc tray being moved to the ejection position, and this forms an inclined posture (lowered position) with respect to the main body.
In these disc drives, if a downward force acts on the sled mechanism unit due to a shock such as the disc drive being dropped or the like in the disc tray ejection state, the front end of the sled mechanism unit at the lowered position is forced even lower. When such an accident is happened, there is the risk that the sled mechanism unit will collide with other elements and cause damage thereto, or the sled mechanism unit itself will become damaged by collision with the bottom portion of the main body. In order to avoid such problems, in the prior art, a protruding stopper was formed on the undersurface of the front end portion of the chassis of the sled mechanism unit so that when the sled mechanism unit is at the lowered position, this stopper makes contact with the bottom portion of the main body.
The prior art disc drive having the above stopper prevents the front end portion of the sled mechanism unit from being lowered during shocks. However, in the case where such prior art structure receives a relatively strong shock, the stopper becomes a support point which enables the rear end portion of the sled mechanism unit to be lowered. The lowered rear end portion will collide with the main circuit substrate provided on the underside of the sled mechanism unit, so that there is the risk that the main circuit substrate will be damaged.